1. Field of Invention
This invention relates to electroplating and more particular to the localized plating of different areas of a singular part with various metals.
2. Description of Related Art
The following art describes the present state of this field:
Electroplating is a coating process for metals to be applied onto a basis metal surface. The coating or plating process is accomplished by means of an electrolyte solution which enables the to be plated metal to be deposited from either metal chip anodes—same metal as to be plated—or neutral metal anodes for plating from the electrolyte through application of a current. The current is supplied by means of a rectifier or power supply. The current is variable whereby the voltage is low and constant. The positive terminal of the rectifier is connected to the anode and the negative terminal to the to be plated part or cathode. Both the anode and parts or cathode typically are fully submerged in the electrolyte. The electrolyte is water based with dissolved salts thus making the electrolyte conductive sustaining a relative low electrical resistance. Once current is applied to the now closed circuit the metal is being deposited onto the part's surface. In case of precious metal plating and specifically gold the gold is suspended in form of gold salts in the electrolyte. The current will enable the gold to be carried out of suspension and deposited onto the part. Whichever portion of the part is selected to be submerged in the electrolyte that is the portion, which will be plated with gold. These electrical contacts come in many configurations and sizes. When the contacts are being plated they are connected with a contactor for the application of current for the plating process. As there is a plurality of contacts being plated in one cycle it is essential that all contacts have a proper connection to the power supply via a contactor as such at least one contactor is assigned to one contact. Location and presentation of the contacts is accomplished with a pallet having an array of through holes arranged in an equally spaced array in such a way that the holes are in alignment vertically with locator sleeves in coaxial fashion provided by a locator plate below the pallet. When the holes of the pallet are properly aligned to be coaxial with the locator sleeves below a contact or other long cylindrical object can be inserted with its far end coming to rest on a locator ledge of the sleeve. Once all holes are filled with the components the plating process can commence. Thus the components can now be exposed to the electrolyte liquid for coating same components in a localized and predetermined area of the component. This type of plating process is commonly known as selective plating meaning that gold or other applicable precious metal is being deposited exclusively in strategic areas of the contact. Strategic areas are where the mating of female to male contact takes place for proper electric conductance once assembled in a connecting device. Specifically applicable to female contacts better known as socket contacts the selective plating as present art teaches does not minimize gold consumption. The reason for this is that the mating end of the contact is exposed to the electrolyte whole meaning that not exclusively the inside diameter or mating area is being plated with thick gold but the outer diameter is being plated with an even thicker layer of gold simultaneously. The reason for this is that the outer diameter of the contact is exposed to the electrolyte at a higher degree in terms of volumetric exchange thereof than the inside diameter of the contact thereby resulting in a higher plating efficiency for the outside diameter. Although prior art selective plating remains to be an economically viable process application it does not reduce gold consumption nearly to the degree as is desirable.
No prior art device is known to achieve discrete plating of female contacts as a method and apparatus for electroplating selected portions of the female contacts and specifically describing a method wherein aforesaid are plated simultaneously, consistently and accurately wherein all selected portions of the contacts not to be plated or at least to be plated with a minimum thickness remain so consistently not plated or at least plated by resulting in a minimum thickness respectively.